Exploring the Circle

What is the formula for the circumference of a circle?

• C = 2r

• C = πr^2

• C = 2πr

• C = πd

Define the term 'radius' in relation to a circle.

• The radius is the distance between two points on the circumference.

• The radius is the area enclosed by the circle.

• The radius is the distance from the center to the circumference of a circle.

• The radius is the diameter of the circle.

What is the area of a circle with a radius of 5 cm?

• 31.4 cm²

• 50 cm²

• 78.5 cm²

• 100 cm²

Name the different types of circles based on their properties.

• Hexagonal circles

• Square circles

• Elliptical circles

• Concentric circles, tangent circles, intersecting circles, unit circles, circumcircles

What is a concentric circle?

• A circle that shares the same center with another circle.

• A circle that intersects with another circle at two points.

• A circle that is larger than another circle.

• A circle that has a different center than another circle.

Explain the term 'diameter' in a circle.

• The diameter is a line segment that connects any two points on the circle.

• The diameter is the distance around the circle.

• The diameter is half the length of the radius.

• The diameter is the longest chord of a circle, passing through the center.

How do you find the center of a circle?

• The center is always at the top of the circle.

• The center is located at the midpoint of the diameter.

• The center of a circle is found at the intersection of the perpendicular bisectors of any two chords.

• The center can be found by measuring the radius.

What is the relationship between the radius and diameter?

• The diameter is twice the radius.

• The diameter is half the radius.

• The radius is twice the diameter.

• The radius and diameter are equal.

How can you divide a circle into equal parts?

• By folding the circle in half

• By cutting the circle with a straight line

• By measuring equal angles from the center or using a compass to mark equal intervals on the circumference.

• By using a ruler to measure the diameter

What is a semicircle?

• A semicircle is a quarter of a circle.

• A semicircle is half of a circle.

• A semicircle is a triangle.

• A semicircle is a full circle.